Material metering system

Abstract

A material metering method which is executed by way of multistage metering including a memory in which a target metering time for the each stage of metering except for a first stage of metering is memorized, each of the target time including unstable metering time for drop amount of material whose drop amount per unit time after changed from prior stage of the metering is unstable; a metering time measuring unit for measuring an actual metering time at the each stage of metering; and a set value correction unit for correcting the supply mass switch value at each stage of the metering except for the first stage of metering based on the target metering time and the actual metering time after performing one batch metering, whereby the entire metering time for subsequent batch metering to be performed is more reduced than one batch metering performed.

Description

TECHNICAL FIELD[0001]The present invention relates to an improvement of a material metering system for metering material per a fixed amount by supplying material such as powdered or granular material from a hopper.BACKGROUND ART[0002]Conventionally, one batch metering method is well known such that material stored in a hopper is dropped from a material outlet by opening a flap damper or a slide shutter provided at the lower part of the hopper and is received in a meter having a load cell or a mass measuring means of differential transformer type or of frequency type, and a material discharge is controlled to be stopped when the mass reaches a predetermined amount while executing a real time measurement.[0003]According to this metering control method by mass metering, there is a height difference between the material outlet and the meter, so that the dropping material is further supplied in the meter after the mass metered by the mass measuring means reaches at a predetermined amount...

AI Technical Summary

Benefits of technology

[0020]According to the material metering system of the present invention, a set value correction means is designed to correct the supply mass switch value at each stage except for the first stage by a predetermined algorism based on the target metering time, the actual metering time and the supply mass switch value. Therefore, the supply mass switch value is corrected in such a manner that the metering time at each stage comes close to the target metering time, thereby achieving optimization of the supply mass switch value at each stage for rapid and accurate metering.

[0021]Further, according to the present invention in which the supply mass switch value at each stage is optimized by correcting at plural times, a little correction is stepwisely executed so that a safe and sure metering can be executed without failure before obtaining an appropriate value.

[0022]Still further according to the present invention which executes one of a standard correction which is based on the difference of the actual metering time and the target metering time or the correction larger than the standard correction when the actual metering time is deviated from the target metering time more than a predetermined threshold value, correction depending on the situation can be executed and the time for optimization can be reduced.

Problems solved by technology

However, the actual amount of residual dropping material is varied at each metering and the accidental error for the predicted value of residual dropping material often becomes large when the outlet is closed and its opening is specifically large.

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